At the end of the race his legs and he fell down on the ground.
A. gave out
B. gave off
C. worn out
D. used up
网友回答
(答案→)A. gave out
B. gave off
C. worn out
D. used up
解析：考查动词短语：A. gave out用尽，耗尽，精疲力竭（不及物动词短语）B. gave off散发， C. worn out用尽，（这是过去分词的形式，不能做谓语）D. used up用完（及物动词短语），句意：在比赛结束的时候，他的腿精疲力竭，倒在地上。选A。